2003 636 Idle Problem

[Twite]

This one has me stumped:
Bike idles fine until you touch the throttle. Bike revs down slowly, sometimes sticking, other times holding a high idle for several seconds before returning to stock idle, or dying completely.
If I adjust the idle to a higher setting (using idle adjuster), it does not rev until I use the throttle. With a higher idle set, the bike returns to low idle under any load.
If I ride the bike down the street it has tons of power through all gears, however if I close the throttle and pull in the clutch the engine dies.
Engine behaves this way hot and cold.



(The fuel light is broken, there is plenty of gas)

Things I have replaced, changed, adjusted:

- Head has been freshly ported and polished, valves adjusted and
timed properly. New timing chain and guides.
- Today I double checked valve clearances and timing.
- 3 different throttle bodies, and 3 different sets of TB sensors.
- throttle body seats (connecting pieces between TB and head)
- Spark plugs
- Coils
- Valve cover (trying anything!)
- Wiring harness
- Battery
- ECU
- Stator
- Went through all grounds confirming good connection.
- airbox
- 2 different exhaust cans (one stock)
- cam chain tensioners (stock and manual)
- fuel pumps
- cam position sensor


Thoughts?

[vegasrider2005]

subscribed, good luck

[J Blox]

I hope this is just a coincidence but this is what one of my motors did after a head swap and then it dropped a valve and grenaded the motor.

I wish I could give better help

[Twite]

Originally Posted by J Blox

I hope this is just a coincidence but this is what one of my motors did after a head swap and then it dropped a valve and grenaded the motor.

I wish I could give better help

It idled like this also?

[Paul]

i think apex had an idle problem which is why he had to ride ernies bike during one of the xdl events... did u ask him?

[Twite]

Here's a thought. Since the head is ported and polished, would I need to tune/re-map? Faster airflow means air/fuel ratio is off? Affected idle???

[Diesel_Stunts]

In theory you would need a new flash or map, same thing. How does it start after it kills its self when your romping on it and pull the clutch in? If it starts hard, it could be loading up on fuel and just flooding out?

EDIT: Maybe check your Coolant temp sensor also?

[M.F. Mall Cop]

Nice to see that even the pro's are human and have bike problems sometimes. Good luck fixing it tho, ive got no clue.

[J Blox]

Originally Posted by Twite

It idled like this also?

It was very very similar. It was hard to start when it was cold tho. Didn't look like u had that problem. When u give it throttle input does it matter how big or small it is? With mine u had to start with a very slight throttle turn and then could crack it. Or it would not rev at all.

[J Blox]

Damn and I looked through ur list. Looks like u changed all the things I could think it would be electrically or even the cam chain tension.


And with the tune thing. If u only did a mild port and polish you are just changing how air
Flows and making it more efficient. Unless u went really overboard and bigger valves I doubt your tune would be that far off.